The invention relates to a height-adjustable support for semi-trailers or the like. Such supports are attached in pairs at the front of semi-trailers and, in the fast gear, can be brought into the support or transport position and, in the low gear, can be used to lift the front region of the semi-trailer, should this be necessary for hitching.
Exemplary supports are known from EP 0 972 689 B1 and DE 88 13 558 U1. In each of these supports, a diameter-sized spur gearwheel is located on the output shaft for the low gear, which is covered by the housing of a transmission seated on the outside on the shaft tube. Thus, it results that between the center of the output shaft and the upper edge of the transmission housing there is a large distance which unfavorably increases the construction height of these supports. A further prior art document is DE 198 36 635 C5. In this so-called device for supporting a semi-trailer of a semi-trailer towing vehicle, a diameter-sized low-gear gearwheel is seated on an output shaft or transmission driven shaft, respectively, wherein the gearwheel is arranged in a plane extending vertically within the outer sleeve and covered by a hood. Also in this device the distance between the center of the output shaft and its upper end is unfavorably great. The disadvantages described are representative of the supports for semi-trailers available on the market in that they increase the overall construction height in the upwards direction and in that they make little use of the available building space so that they provide little design flexibility when it comes to extending the semi-trailer. This is particularly blatant in the case of large-capacity semi-trailers whose frames are necessarily extremely low-lying. Here, only supports with a small overall construction height can be employed. If, however, above the output shaft there is already a construction height proportion which is not used as lifting height, a small overall construction height can only be achieved by reducing the lifting height of the extendable and retractable support part. This means that the ground clearance for operation cannot be optimal or becomes totally impermissible, thus rendering the use of the support impossible.
It is an object of the invention to provide a height-adjustable support for semi-trailers or the like, where the construction height proportion, defined as the distance between the center of the output shaft and its upper end, is favorably and clearly smaller than in conventional supports and which support has a compact design and can be manufactured cost-effectively.